Do i really need the CoreAVC codec ? (1 Viewer)

MageMinds

Portal Pro
January 29, 2007
99
5
Home Country
Canada Canada
Windows 7 codec is unable to play certain files, I can't remember which one, but I had problem playing some mkv files (from The Scene) when I first installed Windows 7 Retail. Media Foundation prevent users like us to install the codec we want, doing that Microsoft may have solved the codec mayhem for non technical ppl though.
 

magao

Portal Member
December 22, 2008
44
3
Home Country
There are definitely limitations on what can be played back using DxVA (especially on AMD cards) - numbers of reference frames, etc. Many fansubbed anime releases for example exceed these limitations.

CoreAVC 2.0 removes or reduces most of these limitations, so there are a lot more files that can be offloaded. In addition, CoreAVC will determine if it is capable of playing back using hardware offloading, and if not will automatically use software, so quality will not suffer unlike if you pass an incompatible encoding to DxVA (which will produce green blocks, etc).

CoreAVC does use a little more CPU than DxVA even when hardware offloading is working - the decoded video is passed back from the video card for post-processing, then passed back to the video card by the renderer.

BTW, CoreAVC 2.1 will apparently include DxVA as well, so hopefully its algorithm will be:

1. Can we use DxVA (compatible encoding for video card, connected directly to renderer)?

2. Can we use CUDA (compatible nVidia card, compatible encoding)?

3. Use software decoding.

I'm guessing that the reason you're getting blocky decoding with Matroska is that the default MP4 and MKV profiles with Handbrake have different encoding settings (I know they do for audio - it won't let you put a DD or DTS stream into MP4 for example). Make sure you confirm that the encoding settings are identical for comparison. MKV and MP4 are just containers.

In general, MKV is the preferred container these days, and looks likely to become the dominant container for the next while (has significant hardware support, can hold any kind of data e.g. subtitles, embedded fonts, etc).
 

tourettes

Retired Team Member
  • Premium Supporter
  • January 7, 2005
    17,301
    4,800
    Windows 7 codec is unable to play certain files, I can't remember which one, but I had problem playing some mkv files (from The Scene) when I first installed Windows 7 Retail. Media Foundation prevent users like us to install the codec we want, doing that Microsoft may have solved the codec mayhem for non technical ppl though.

    Just to correct that a bit: Media Foundation itself is not preventing anything. It is a new framework (similar to Directshow). It is the applications using Media Foundation that are posing those restrictions.

    Also I think Media Foundation is much better framework than the Directshow, too bad that there are almost no codecs available for it. Same goes for the splitters etc. Hopefully that changes in few next year.
     

    ga_mueller

    New Member
    October 17, 2009
    3
    0
    Home Country
    United States of America United States of America
    Wow. I finally solved my blocky h264 DxVA during dark scenes with high profile encoding with Handbrake.... GBPVR/8400GS/XPSP3... DO NOT use "Dynamic Contrast Enhancement" in NVidia setup, as this was the cause of my problems...
     

    kszabo

    MP Donator
  • Premium Supporter
  • December 6, 2007
    796
    86
    Germany, Bayern
    Home Country
    Hungary Hungary
    my answer to the Question of the topic:
    no, you don´t need it really, if your nVidia 7300 can DXVA (afaik it can). Just grab the MPC-HC codec with MPC-HC subtitle engine.
     

    Users who are viewing this thread

    Top Bottom